A Multi-Static Primary Surveillance Radar (MSPSR) includes a transmitter and a plurality of receivers. The transmitter radiates a pulsed radio wave. Each receiver receives a reflected wave (echo signal) returned from a target. The position (range) of the target can be estimated by performing elliptical positioning for each receiver based on the time difference between transmission and reception. The target can be specified by hyperbolic positioning between a plurality of transmission/reception channels using the combinations of the transmitter and the receivers.
In some cases, the receiver cannot correctly receive the reflected wave because of the reception environment, reception sensitivity, or the like. This leads to deterioration of the observation accuracy and tracking performance and errors in position estimation. It is demanded to cope with these problems.